The proposed research is to study the effect of long term sympathectomy on the metabolic activity, specifically lipids in the arterial wall, under normal conditions as a function of age and with different perturbations, as well as the effect of the sympathetic nervous system on the influx of the blood-borne lipids in the arteria wall. The experiments will be performed on rabbits, and the plasma lipids will be periodically determined. After termination of the experiments, the arteries will be removed, the lipids extracted and their amount and composition will be determined. Quantitative histology will accompany the lipid analysis. The experimental conditions will be systematically altered to analyze the regulatory of the lipid metabolism in the vessel wall.